cregit-Linux how code gets into the kernel

Release 4.11 drivers/usb/usbip/vudc_transfer.c

/*
 * Copyright (C) 2015 Karol Kosik <karo9@interia.eu>
 * Copyright (C) 2015-2016 Samsung Electronics
 *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
 *
 * Based on dummy_hcd.c, which is:
 * Copyright (C) 2003 David Brownell
 * Copyright (C) 2003-2005 Alan Stern
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/usb.h>
#include <linux/timer.h>
#include <linux/usb/ch9.h>

#include "vudc.h"


#define DEV_REQUEST	(USB_TYPE_STANDARD | USB_RECIP_DEVICE)

#define DEV_INREQUEST	(DEV_REQUEST | USB_DIR_IN)

#define INTF_REQUEST	(USB_TYPE_STANDARD | USB_RECIP_INTERFACE)

#define INTF_INREQUEST	(INTF_REQUEST | USB_DIR_IN)

#define EP_REQUEST	(USB_TYPE_STANDARD | USB_RECIP_ENDPOINT)

#define EP_INREQUEST	(EP_REQUEST | USB_DIR_IN)


static int get_frame_limit(enum usb_device_speed speed) { switch (speed) { case USB_SPEED_LOW: return 8 /*bytes*/ * 12 /*packets*/; case USB_SPEED_FULL: return 64 /*bytes*/ * 19 /*packets*/; case USB_SPEED_HIGH: return 512 /*bytes*/ * 13 /*packets*/ * 8 /*uframes*/; case USB_SPEED_SUPER: /* Bus speed is 500000 bytes/ms, so use a little less */ return 490000; default: /* error */ return -1; } }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski62100.00%1100.00%
Total62100.00%1100.00%

/* * handle_control_request() - handles all control transfers * @udc: pointer to vudc * @urb: the urb request to handle * @setup: pointer to the setup data for a USB device control * request * @status: pointer to request handling status * * Return 0 - if the request was handled * 1 - if the request wasn't handles * error code on error * * Adapted from drivers/usb/gadget/udc/dummy_hcd.c */
static int handle_control_request(struct vudc *udc, struct urb *urb, struct usb_ctrlrequest *setup, int *status) { struct vep *ep2; int ret_val = 1; unsigned int w_index; unsigned int w_value; w_index = le16_to_cpu(setup->wIndex); w_value = le16_to_cpu(setup->wValue); switch (setup->bRequest) { case USB_REQ_SET_ADDRESS: if (setup->bRequestType != DEV_REQUEST) break; udc->address = w_value; ret_val = 0; *status = 0; break; case USB_REQ_SET_FEATURE: if (setup->bRequestType == DEV_REQUEST) { ret_val = 0; switch (w_value) { case USB_DEVICE_REMOTE_WAKEUP: break; case USB_DEVICE_B_HNP_ENABLE: udc->gadget.b_hnp_enable = 1; break; case USB_DEVICE_A_HNP_SUPPORT: udc->gadget.a_hnp_support = 1; break; case USB_DEVICE_A_ALT_HNP_SUPPORT: udc->gadget.a_alt_hnp_support = 1; break; default: ret_val = -EOPNOTSUPP; } if (ret_val == 0) { udc->devstatus |= (1 << w_value); *status = 0; } } else if (setup->bRequestType == EP_REQUEST) { /* endpoint halt */ ep2 = vudc_find_endpoint(udc, w_index); if (!ep2 || ep2->ep.name == udc->ep[0].ep.name) { ret_val = -EOPNOTSUPP; break; } ep2->halted = 1; ret_val = 0; *status = 0; } break; case USB_REQ_CLEAR_FEATURE: if (setup->bRequestType == DEV_REQUEST) { ret_val = 0; switch (w_value) { case USB_DEVICE_REMOTE_WAKEUP: w_value = USB_DEVICE_REMOTE_WAKEUP; break; case USB_DEVICE_U1_ENABLE: case USB_DEVICE_U2_ENABLE: case USB_DEVICE_LTM_ENABLE: ret_val = -EOPNOTSUPP; break; default: ret_val = -EOPNOTSUPP; break; } if (ret_val == 0) { udc->devstatus &= ~(1 << w_value); *status = 0; } } else if (setup->bRequestType == EP_REQUEST) { /* endpoint halt */ ep2 = vudc_find_endpoint(udc, w_index); if (!ep2) { ret_val = -EOPNOTSUPP; break; } if (!ep2->wedged) ep2->halted = 0; ret_val = 0; *status = 0; } break; case USB_REQ_GET_STATUS: if (setup->bRequestType == DEV_INREQUEST || setup->bRequestType == INTF_INREQUEST || setup->bRequestType == EP_INREQUEST) { char *buf; /* * device: remote wakeup, selfpowered * interface: nothing * endpoint: halt */ buf = (char *)urb->transfer_buffer; if (urb->transfer_buffer_length > 0) { if (setup->bRequestType == EP_INREQUEST) { ep2 = vudc_find_endpoint(udc, w_index); if (!ep2) { ret_val = -EOPNOTSUPP; break; } buf[0] = ep2->halted; } else if (setup->bRequestType == DEV_INREQUEST) { buf[0] = (u8)udc->devstatus; } else buf[0] = 0; } if (urb->transfer_buffer_length > 1) buf[1] = 0; urb->actual_length = min_t(u32, 2, urb->transfer_buffer_length); ret_val = 0; *status = 0; } break; } return ret_val; }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski55099.10%133.33%
Krzysztof Opasiak30.54%133.33%
Jai Krishna20.36%133.33%
Total555100.00%3100.00%

/* Adapted from dummy_hcd.c ; caller must hold lock */
static int transfer(struct vudc *udc, struct urb *urb, struct vep *ep, int limit) { struct vrequest *req; int sent = 0; top: /* if there's no request queued, the device is NAKing; return */ list_for_each_entry(req, &ep->req_queue, req_entry) { unsigned int host_len, dev_len, len; void *ubuf_pos, *rbuf_pos; int is_short, to_host; int rescan = 0; /* * 1..N packets of ep->ep.maxpacket each ... the last one * may be short (including zero length). * * writer can send a zlp explicitly (length 0) or implicitly * (length mod maxpacket zero, and 'zero' flag); they always * terminate reads. */ host_len = urb->transfer_buffer_length - urb->actual_length; dev_len = req->req.length - req->req.actual; len = min(host_len, dev_len); to_host = usb_pipein(urb->pipe); if (unlikely(len == 0)) is_short = 1; else { /* send multiple of maxpacket first, then remainder */ if (len >= ep->ep.maxpacket) { is_short = 0; if (len % ep->ep.maxpacket > 0) rescan = 1; len -= len % ep->ep.maxpacket; } else { is_short = 1; } ubuf_pos = urb->transfer_buffer + urb->actual_length; rbuf_pos = req->req.buf + req->req.actual; if (urb->pipe & USB_DIR_IN) memcpy(ubuf_pos, rbuf_pos, len); else memcpy(rbuf_pos, ubuf_pos, len); urb->actual_length += len; req->req.actual += len; sent += len; } /* * short packets terminate, maybe with overflow/underflow. * it's only really an error to write too much. * * partially filling a buffer optionally blocks queue advances * (so completion handlers can clean up the queue) but we don't * need to emulate such data-in-flight. */ if (is_short) { if (host_len == dev_len) { req->req.status = 0; urb->status = 0; } else if (to_host) { req->req.status = 0; if (dev_len > host_len) urb->status = -EOVERFLOW; else urb->status = 0; } else { urb->status = 0; if (host_len > dev_len) req->req.status = -EOVERFLOW; else req->req.status = 0; } /* many requests terminate without a short packet */ /* also check if we need to send zlp */ } else { if (req->req.length == req->req.actual) { if (req->req.zero && to_host) rescan = 1; else req->req.status = 0; } if (urb->transfer_buffer_length == urb->actual_length) { if (urb->transfer_flags & URB_ZERO_PACKET && !to_host) rescan = 1; else urb->status = 0; } } /* device side completion --> continuable */ if (req->req.status != -EINPROGRESS) { list_del_init(&req->req_entry); spin_unlock(&udc->lock); usb_gadget_giveback_request(&ep->ep, &req->req); spin_lock(&udc->lock); /* requests might have been unlinked... */ rescan = 1; } /* host side completion --> terminate */ if (urb->status != -EINPROGRESS) break; /* rescan to continue with any other queued i/o */ if (rescan) goto top; } return sent; }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski50299.80%150.00%
Jai Krishna10.20%150.00%
Total503100.00%2100.00%


static void v_timer(unsigned long _vudc) { struct vudc *udc = (struct vudc *) _vudc; struct transfer_timer *timer = &udc->tr_timer; struct urbp *urb_p, *tmp; unsigned long flags; struct usb_ep *_ep; struct vep *ep; int ret = 0; int total, limit; spin_lock_irqsave(&udc->lock, flags); total = get_frame_limit(udc->gadget.speed); if (total < 0) { /* unknown speed, or not set yet */ timer->state = VUDC_TR_IDLE; spin_unlock_irqrestore(&udc->lock, flags); return; } /* is it next frame now? */ if (time_after(jiffies, timer->frame_start + msecs_to_jiffies(1))) { timer->frame_limit = total; /* FIXME: how to make it accurate? */ timer->frame_start = jiffies; } else { total = timer->frame_limit; } /* We have to clear ep0 flags separately as it's not on the list */ udc->ep[0].already_seen = 0; list_for_each_entry(_ep, &udc->gadget.ep_list, ep_list) { ep = to_vep(_ep); ep->already_seen = 0; } restart: list_for_each_entry_safe(urb_p, tmp, &udc->urb_queue, urb_entry) { struct urb *urb = urb_p->urb; ep = urb_p->ep; if (urb->unlinked) goto return_urb; if (timer->state != VUDC_TR_RUNNING) continue; if (!ep) { urb->status = -EPROTO; goto return_urb; } /* Used up bandwidth? */ if (total <= 0 && ep->type == USB_ENDPOINT_XFER_BULK) continue; if (ep->already_seen) continue; ep->already_seen = 1; if (ep == &udc->ep[0] && urb_p->new) { ep->setup_stage = 1; urb_p->new = 0; } if (ep->halted && !ep->setup_stage) { urb->status = -EPIPE; goto return_urb; } if (ep == &udc->ep[0] && ep->setup_stage) { /* TODO - flush any stale requests */ ep->setup_stage = 0; ep->halted = 0; ret = handle_control_request(udc, urb, (struct usb_ctrlrequest *) urb->setup_packet, (&urb->status)); if (ret > 0) { spin_unlock(&udc->lock); ret = udc->driver->setup(&udc->gadget, (struct usb_ctrlrequest *) urb->setup_packet); spin_lock(&udc->lock); } if (ret >= 0) { /* no delays (max 64kb data stage) */ limit = 64 * 1024; goto treat_control_like_bulk; } else { urb->status = -EPIPE; urb->actual_length = 0; goto return_urb; } } limit = total; switch (ep->type) { case USB_ENDPOINT_XFER_ISOC: /* TODO: support */ urb->status = -EXDEV; break; case USB_ENDPOINT_XFER_INT: /* * TODO: figure out bandwidth guarantees * for now, give unlimited bandwidth */ limit += urb->transfer_buffer_length; /* fallthrough */ default: treat_control_like_bulk: total -= transfer(udc, urb, ep, limit); } if (urb->status == -EINPROGRESS) continue; return_urb: if (ep) ep->already_seen = ep->setup_stage = 0; spin_lock(&udc->lock_tx); list_del(&urb_p->urb_entry); if (!urb->unlinked) { v_enqueue_ret_submit(udc, urb_p); } else { v_enqueue_ret_unlink(udc, urb_p->seqnum, urb->unlinked); free_urbp_and_urb(urb_p); } wake_up(&udc->tx_waitq); spin_unlock(&udc->lock_tx); goto restart; } /* TODO - also wait on empty usb_request queues? */ if (list_empty(&udc->urb_queue)) timer->state = VUDC_TR_IDLE; else mod_timer(&timer->timer, timer->frame_start + msecs_to_jiffies(1)); spin_unlock_irqrestore(&udc->lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski65398.20%150.00%
Krzysztof Opasiak121.80%150.00%
Total665100.00%2100.00%

/* All timer functions are run with udc->lock held */
void v_init_timer(struct vudc *udc) { struct transfer_timer *t = &udc->tr_timer; setup_timer(&t->timer, v_timer, (unsigned long) udc); t->state = VUDC_TR_STOPPED; }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski42100.00%1100.00%
Total42100.00%1100.00%


void v_start_timer(struct vudc *udc) { struct transfer_timer *t = &udc->tr_timer; dev_dbg(&udc->pdev->dev, "timer start"); switch (t->state) { case VUDC_TR_RUNNING: return; case VUDC_TR_IDLE: return v_kick_timer(udc, jiffies); case VUDC_TR_STOPPED: t->state = VUDC_TR_IDLE; t->frame_start = jiffies; t->frame_limit = get_frame_limit(udc->gadget.speed); return v_kick_timer(udc, jiffies); } }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski91100.00%1100.00%
Total91100.00%1100.00%


void v_kick_timer(struct vudc *udc, unsigned long time) { struct transfer_timer *t = &udc->tr_timer; dev_dbg(&udc->pdev->dev, "timer kick"); switch (t->state) { case VUDC_TR_RUNNING: return; case VUDC_TR_IDLE: t->state = VUDC_TR_RUNNING; /* fallthrough */ case VUDC_TR_STOPPED: /* we may want to kick timer to unqueue urbs */ mod_timer(&t->timer, time); } }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski72100.00%1100.00%
Total72100.00%1100.00%


void v_stop_timer(struct vudc *udc) { struct transfer_timer *t = &udc->tr_timer; /* timer itself will take care of stopping */ dev_dbg(&udc->pdev->dev, "timer stop"); t->state = VUDC_TR_STOPPED; }

Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski39100.00%1100.00%
Total39100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Igor Kotrasinski205199.13%125.00%
Krzysztof Opasiak150.72%250.00%
Jai Krishna30.14%125.00%
Total2069100.00%4100.00%
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